Improvement in scroll-saws



REUDEN MCCHESNEY, OF BIRMINGHAM,CONNECTICUT, ASSIGNOR T() HIM- SELF,THCMAS L. CORNELL, AND SIDNEY CORNELL.

Letters Patent No. 108,921, dated November 1, 1870.

. IMPROVEMENT iN scRoLL-sAws.

The Schedule referred to in these Letters Patent making part of thesame.

To all' whom it may conce/rn B e it known that I, RnnBnN MoOnnssnr, ofBirmingham, in" the county of New Haven and State of Connecticut, haveinvented certain new and useful Improvements in Scroll Sawing-Machines;and I do hereby declare that the following is a full, clear, and exactdescription thereof', reference being had to the accompanying drawingmaking part of this specification, in which- Y i Figure 1, plate 1, is asection through the frame of the machine, taken in the vertical planeindicated by the dotted line a: x, in fig. 6.

Figure 2, plate l, is the front view of the upper boelt'for the saw,andthe guides therefor, showing, .by a section 0f one of the guide-rods,the method ot' oiling the block. r l

Figures 3, 4, and 5, plate 1, show the construction ol' the sawblocks,'and also the device for adjusting the saw for rake.

Figure 6, plate 2, is a front elevation of the machine with the frontportion of the table removedtoexpse the adjustable pulley-carryingslide.

Figures 7 and 8, plate 2, are views in'detail, showing the method ofoiling the lower saw-block through the table and guide-rods.

Figure 9, plate 2, shows a portion of a Iilexible strap,

. and a. stili" rod for keeping the saw under strain.-

Similar letters of reference indicate corresponding parts iul theseveral figures.

This invention relates to certainv novel improvements in machinesforsa'wing all kinds of scroll-work, wherein the saw is held undertension by means `of flexible connections working around pulleys.

The nature of myv invention consists- First, in the combination of..comparatively stiff and ineirtensible connections with flexibleconnections, as

means for keeping the saw under proper tension.

Second, iu providing for oiling the saw'- blocks through the guides' onwhich these blocks work.

Third, in providing for giving the saw ,any desired degree of rake, bysplitting the saw-stirrup ofthe upper saw-block, and using au adjustableback rest, in combination with a clamping screw for 'positively rovtaining the back-rest in place.

Fourth, in a divided saw-carryingblock, having an elastic materialinterposed between its halves, and also clamping-screws for securing thetwo halves together' and adjusting them for wear.

To enable others skilled in the art to understand my invention, I willdescribe its construction and operation.

In the accompanying drawing A represents thc table-top, and

B, the frame, supporting the same, which may be constructed in anysuitable manner.

B is a rigid pendant, for holding the lower guide D, and

B2is an arched frame, rising abovethe table-top A, for supporting theupper guide D and pulley segment F1.

The guide D and the pulley segment F may be applied to a pendant'whichis secured to the ceiling timbers of the room in'which the machine isarranged.

' lhe saw Sis strained between hooked extensions e et oi'verticallysliding blocks E E.

The slide block E is arranged beneath the table-top AA,.and moves onguideods c c', appliedto offsets ot' the guide D.

This lower block E has a pitman-rod, I), applied to it,- the lower endof which lpitmau is applied to a wristpin ou a crank-wheel, J.

This wheel is keyed on a shaft, J', carrying fast-audloose pulleys j j',as shown in g. 1.

' The-guide-rods c c are bored out, as shown in fig. 8, Iplate 2, and,at the lower termination of the bores out-lets are made laterallythrough the rods.

,The upper ends of these hollow rods arecapped by thimbles T T, throughthe upper ends of which holes are made that register with holes o o madethrough plate L.

To plate L circular rotary covers u u are applied,

which are also perforated, and which, like plate L, are let into thetable-top Hush with its surface.v The lateral intersecting outletsthrough rods c' c' are, say about the middle of their length, so that,when the block- E isin motion a'nd oil is vput into the upper ends ofthe rods, this block will be lubricated.

'lhe oil is introduced into the rods o c' through the perforatious madethrough covers n, plate L, and thimbles T T, after which a slight turnof the covers u u will cause them `to close the inlets and preventtheentrance of dust into the rods. To prevent a too l'apid ow'of the oilto the block E, some soft porous material may be introduced into thetubular portions of the rods c.

The sliding block E is arranged above the table, and

moves on guide-rods c c, applied rigidly to off-sets b' of the guide D.

The guides c c are borcdout precisely as described for guides'c' c', andare provided, at theirupper end-s, with oil-receiving cups o o.

At the lower end of the tubular portion of each rod outlets are made,for the supply of oil to the block E', as it rises and descends.

The hooked extension or stirrnp e is split vertically, as shown in figs.3 and 5, to receive the saw, and also to receive a piu, 1J. This pinaiords a back-rest or bearing for the upper end of the saw, and canbeadkjnsted en'd'wise for giving the desired rake to the saw.

A clamp-screw, p', is used to draw together the split l portions of thestirrup e, and so confine the pinp that.

,runt effin,

it cannot slip nor work loose during the operation of the machine.

The saw S is strained by means of flexible cannections g gl g2, whichare attached, respectively, to pnlley segments F 11" F2, and to"fstit'connecting-rods (i G. Y

Prior to this part of my invention a flexible strap or belt extendedfrom one end ofthe saw, over pulleys, to the other end ot' the saw, forthc purpose of keeping the s aw under tension but it was found that thematerial used for the said belt or strap would stretch, and wasmaterially affected bjy hydrometiechanges. lo obviate this, and, at thesame time, to obtainticxibility of the belt at the pulleys, I combine,with the short flexible straps g yl (f, the stiltl rods G G.

'lhe rods will no t be materially `attected by strain on them, and thcstraps, which may be made of rawhide, or other suitable material, are soshort that they will not bc materially shortened or lcngtheued fromsevere strain or other canse.

The pulleys 11 l" F2 may be lnade circular or segmental, and they may bemade with single or double grooves intheir peripheries.

The d'awing shows double grooves in cach pulley, with two short fiexiblcconnections` foreach; but a single groove, with one short flexibleconnection foreach pulley, maybe used.

'lhe flexible connections q y' y2 are, respectively,

secured fast totheir pulleys, so that they cannot slip on them, thusallowing a positive mot-ion to be im- 'l parted to the saw, both in itsup-and-down movements.

' lhe pulley F is appliedto an arm, C', of'an adjustahle piece, Garranged beneath the table-top A, he-

twcen guides. t,

The picce'C, willi its arm C', can be adjusted endwisc, by means of ahand-scre\v, V, .which passes loosely through a fixed bearing, WV, shownin fig. 6.

By this adjustment it will be seen that any desired degree of tensioncan be given to the saw, whether in motion'or atrest. l

Each one of the saw-blocks 1s constructed so that it can be adjusted tocompensate for wear on the guiderods.

By reference to figs. 3, 4, and 5, it will be seen that the block E' iscomposed of two halves, which are clamped together by means ot nuts onscrew-bolts k lt. The tang ,f and hooke are connected together by shankci, which is recessed into the two halves ot' the blocks..

By introducing apiece ot India rubber, s, between 4the shank e2 and oneot' the block sections, these sections can be properly set up t-o theirIguide-rodsand compensation allowed for adjustment as the bearingsurfaces wear away. y

rlhe -rubber s will prevent the n uts or bolts 7a L from wearing loose.4In this way I am enabled to keep the saw-blocks properly set up totheir guide-rods and prevent irregular motion of the saw.

Having described my invention,

XVhat I claim' as new, and desire to secure by Letters latent,is

1. The combination ofthe two rods G G, three iexible sections g g g2,three segments or pulleys F F1 F, saw S, blocks E E', straight slidingdevice O', and' ad'- justing device W V, all 'arranged and operating inthe manner and for the purpose herein described.

2. Thecombination otheblocltE or 1", constructed as shown, and theperforated hollowl guide-rods c c, carrying oil, as an oil-chamber, andsupplying the same to the external -head-bloek'E or foot-block E of asaw which is guided by them, substantially asdescribed.-

3. The movable covers n n, and the thimblcs 'l T, combined with thelowerperforated.guide-rods c' c', substantially as described. p l

4. The split saw-stirrnp c, having, the"adjustable back-rest p andclamp-screw p' applied to it, substantially as described.

5. '.lhe combination of the device e c f, divided sauii4 carrying blockE or E', elastic strip s, screws k k, and nuts, substantially as shownand described.

'A 6. Straight moving adjustable support C' pulley E2,

vflexible. section g2, rods vGr G, pulleys l?1 l?, flexible sections ggl, saw S, and adjustable device V NV, com-- 'bined and arrangedsubstantially in the manner de scribed. v

VVit-nesses: REUBEN MCCHESNEY.

J oHN W. CHAMBERS. D. It. GARDEN.

